You have assigned the same ids to your hidden fields as the ones which the user is to fill out. ids must be unique. It is the defined and unchanged values of the hidden fields which are being submitted.
Change the ids of your hidden fields and all then ought to be well. But the hidden fields seem to have no purpose.
All advice is supplied packaged by intellectual weight, and not by volume. Contents may settle slightly in transit.
All the code given in this post has been tested and is intended to address the question asked.
Unless stated otherwise it is not just a demonstration.